1. Field of Invention
The present invention relates to devices for rotating drill shafts and, more particularly, is directed towards a device for applying torque and thrust to flexible roofdrill shafts.
2. Description of the Prior Art
In the mining industry, falls of mine roofs account for a large percentage of the fatalities that occur in coal mines. Thus, roof control has been a major safety and production consideration. Roof fall fatalities have been greatly reduced in cases where the mine roof is supported with roof bolts that are inserted into holes which are drilled into the mine roof using a drill that is attached to a rigid shaft. As the holes become progressively deeper, the mine worker adds extension sections to the drill shaft. Such an operation requires the worker to be at the head of a roof drilling machine for starting the hole, for adding the extension sections and for inserting the bolts. Flexible roofdrills have been designed for the drilling of roof bolt holes, the flexible roofdrill shaft being significantly greater than the mining height. A need has arisen for a device for applying torque and thrust to such flexible roofdrills.